Cambridge, Mass. — RiboX Therapeutics said the U.S. Food and Drug Administration has granted Regenerative Medicine Advanced Therapy designation to RXRG001, its investigational circular RNA therapy for radiation-induced xerostomia and hyposalivation.
The designation was supported by preliminary clinical data from the ongoing Phase 1/2a SPRINX-1 study. RXRG001 has also received FDA Fast Track designation.
RXRG001 is being evaluated in a first-in-human, multicenter Phase 1/2a trial in U.S. adults with radiation-induced xerostomia and hyposalivation. The dose-escalation study is assessing the safety, tolerability and preliminary efficacy of administering the therapy directly into the ducts of the parotid glands.
“The FDA’s RMAT designation for RXRG001 represents an important milestone for RiboX and recognizes the promising preliminary clinical evidence generated with our circular RNA platform,” said Weiyi Zhang, Ph.D., Co-Founder and Chief Executive Officer of RiboX.
“Radiation-induced xerostomia and hyposalivation can have a significant impact on patients following treatment for head and neck cancer, yet current treatment options are primarily focused on symptom management. We look forward to working closely with FDA as we advance RXRG001 and evaluate its potential to restore salivary gland function for these patients.”
RXRG001 is a proprietary circular RNA therapy encoding human aquaporin-1, or hAQP1, a water-channel protein involved in fluid transport. The RNA is encapsulated in a lipid nanoparticle and administered locally to the salivary glands.
The therapy is designed to enable expression of functional hAQP1 with the goal of restoring saliva production in patients whose salivary glands have been damaged by radiation treatment.
Radiation-induced xerostomia and hyposalivation are common complications of radiation therapy for head and neck cancers. Damage to the salivary glands can result in persistent dry mouth and reduced saliva production, affecting eating, chewing, swallowing and speaking while also contributing to oral and dental problems.
Current treatments are primarily aimed at managing symptoms rather than restoring salivary gland function.
The FDA’s RMAT program is intended to expedite the development and review of regenerative medicine therapies for serious or life-threatening conditions. Qualifying therapies must have preliminary clinical evidence indicating the potential to address an unmet medical need.
The designation can provide sponsors with earlier and more frequent FDA interactions and guidance aimed at supporting efficient clinical development and regulatory review.
RXRG001 is currently being studied in SPRINX-1, identified as NCT06714253, which is evaluating its safety, tolerability and preliminary efficacy in adults with radiation-induced xerostomia and hyposalivation.
